Improvement in plate-printing presses



J. MILLIGrAN:l

. PLATE PRINTING PRESS. N.180,490. Patented Aug.1,187e.

NPETEHS. PHOTOJJTHOGRAPNER. WASHINGTON. DAC- UNITED STATES,y

PATENT EEIOE JAMES MILLIGAN, OE BROOKLYN, NEW YORK.

IMPROVEMENT IN PLATE-PRINTING PRESSES.

Specification formingvpart'of Letters Patent No. 180,490, dated August 1, 1876; application filed Api-i127, 1675. l

.To all 'whom 'it may concern :V

Be it known that I, JAMES MILLIG-AN, of Brooklyn, in the county of Kings and State of New York, have invented au Improvement in Plate-Printing Presses, of which the following is a specification:

Plate -printing presses have been made in which the bed or plank upon which the engraved plate rests has been carried around upon a revolving'table, and the inking or {illing in, wiping, polishing, laying on, pressing, and removing the sheet have been performed successively as the table is revolved progress` ploying four beds, these operations are per! formed simultaneously by different operatives upon diierent plates, thus greatly facilitating the operations.

In the drawing, Figure 1 is a general plan, and Fig. 2 is a vertical section.

The frame a is square and supported upon suitable legs, and this is connected with the inner frame b bythe bars c, and between the frames c b there is the space required for the square bed or plank d to slide as it rests upon the ledges of offsets e; and to support the advancing edge of the plank as it comes into the corner the ledges are extended part of th way across, as seen at e.

In order to move the bed or plank along on the straight side to the vend or angle, and then start the same oli in a direction at right angies to the line of its former movement, I make use of a belt or chain, f, passing around the pulleys g g, and upon this chain there are projecting studs or pins t', that correspond in number with the beds employed. There will generally be four at equal distances apart, as illustrated in Fig. 1 by the full and dotted Y lines. These pins i may be connected, by a link, with the center of the bed at the under side; but I have shown a square opening in the center ofthe bed at the under side, placed diagonally, so that the pin will occupy one angle of this opening while drawing the bed along on one side. lt willthen pass from that angle to the next as the bed arrives at the corner of the frame, and in so doing there will bea-pause in the movement of the bed,

and the bed or plank will be fully moved to its next position by the pin traveling along the inclined side o f this opening as said pin moves with the chain around the roller g at the angle.

The corners of the frame a may be slightly rounded, and the bearing-ledges widened, so that the plank may be free to move with the pin and chain as they turn around the rollers in passing from one straightline to the next.

In order to move the chain I make use of a main shaft, k, bevel-gears l, second shaft m, and bevel-gears n, to the axis of one of the rollers g; and this roller-'should have lugs litting the chain or belt f, so as to move the same reliably. Upon the shaft 7a are the rollers o, .that sus tain the bed or plank d while the impression is given by the blanket-rollenr. This roller r is of usual character, and may be started by a cam-shaped projection coming into contact with the bed or plank. This blanket-rolleris set in adjustable boxes, as usual.

The inking and wiping of the plate will be performed as the plank approaches o ne angle, pauses, and starts again in the next direction. The polishing will be done at or near the next angle. The laying on of the sheet will be at or near the third angle. The impression is then given, and the sheet is removed at or near the fourth angle; and each operative is allowed the time that is occupied in polishing each plate, this being the limit of speed.

rI he sheet will usually be laid on and registered, and the operator guides the paper as it passes under the blanket-roller, and in so doing it is often necessary to pull the paper one way or the other to prevent wrinkling, and the operators fingers are occasionally caught by the blanket-roller, even in hand-presses. Hence, to prevent the possibility of the hand being drawn in when printing by power, I provide a transparent shield, u, made of glass,

and sustained adjustably at the ends, so as to be raised or lowered. This prevents the tingers getting too near the blanket-roller acei-y dentully, and at the same time the paper can be carefully observed and guided.

The plank may be made sufeiently thick and hollow, so as to receive :t lump to heat up the same to any desired temperature to warm the plate.

I'oluim as my inventionl. The rectangular frames a and b, forming a square slide, in which the square plate-bed d is moved, in combination with the chain or belt f, rollers g, impression-roller r, and geur- 

